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How can I use '>' to redirect output in Node.js?

For example, suppose I want to replicate a simple command

echo testing > temp.txt

Here is what I have tried

var util  = require('util'),
    spawn = require('child_process').spawn;

var cat = spawn('echo', ['> temp.txt']);
cat.stdin.write("testing");
cat.stdin.end();

Unfortunately no success

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3 answers


You cannot pass the redirection character (>) as an argument to appear, as this is not a valid argument to the command. You can use exec

spawn instead, which executes any command line you pass in a separate shell, or use this approach:



var cat = spawn('echo', ['testing']);

cat.stdout.on('data', function(data) {
    fs.writeFile('temp.txt', data, function (err) {
        if (err) throw err;
    });
});
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You can either pipe the node console output a la "node foo.js> output.txt" or you can use the fs package to write the file



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echo

doesn't seem to block for stdin:

~$ echo "hello" | echo
~$

^ no way out there ...

So what you can try:

var cat = spawn('tee', ['temp.txt']);
cat.stdin.write("testing");
cat.stdin.end();

I don't know if this will be helpful for you.

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